US3133608A - Bag filling machine - Google Patents

Description

May 19, 1964 E. M. LAU

BAG-FILLING MACHINE 3 Sheets-Sheet 1 Filed 1962 May 19, 1964 E M. LAU BAG-FILLING MACHINE Filed Feb. 5, 1962 3 Sheets-Sheet 2 f7? #92? for. Era/1'72 J17. Zea

May 19, 1964 E. M. LAU 3,133,608

BAG-FILLING MACHINE Filed Feb. 5, 1962 3 Sheets-Sheet 3 parts of the feeding mechanism.

United States Patent 3,133,608 BAG FILLING MACHINE Erwin M. Lau, Bolton, 111., assignor to Black Products Co., Chicago, Ill., a corporation of Illinois Filed Feb. 5, 1962, Ser. No. 171,200 8 Claims. (Cl. 177-118) This inventionrelates to improvements in bag filling machines of the automatic cutoff type. i V

In machines of this type, the bag is suspended from the filling spout. The filling spout is mounted for vertical movement and it bears on the beam of the scale mechanism. When a predetermined amount of material has been fed into the bag, the movement of the beam cuts off the filling operation.

, An object of this invention is to provide a bag filling machine in which the beam axis is parallel to the spout axis so that the position of the bag on the spout will not vary the length of the lever arm, and hence affect the accuracy of the scale mechanism.

Another object is to provide a spout assembly in the form of a suspended element, thus reducing the number of bearing points required and providing a siniplifiedconstruction without sacrifice of sensitivity.

A further object is to provide, in a parallel beam axis type of machine, a beam and spout assembly construction which does not interfere with the location of the various The present application is a continuation-in-part of my copending application, Serial No. 801,143 filed March 23, 1959 now Patent No. 3,062,307, granted November 6, 1962. I

In my aforesaid copending applicatiomthe suspended spout assembly was stabilized against backward swinging movement by a strut which reacted v on the supporting framework. The strut develops a horizontal force, com

ponent which may result in a climbing of'the spout assembly, and this climbing affects the beam in a manner which detracts from the accuracy of the weighing operation. I

3,133,608 Patented May 19, 1964 FIG. 3 is a fragmentary of FIG. 1; i

FIG. 4 is a front elevation of the scale mechanism divorced from the remainder of the machine;

FIG. 5 is a side elevation of FIG. 4;

FIG. 6 is a rear elevation of FIG. 4, but with the, I

ing framework 19. Mounted above the bed plate are feeding mechanism designated generally by the reference numeral 11, and scale mechanism shown in FIGS. 47

A which includes a beam 25, and a suspended spout as- A further object of my invention is to provide a stabilized arrangement which eliminates the use of the strut.

The strut arrangement is not entirely satisfactory for another reason; in certain filling operations, particularly those involving powdery materials, the d-rippage from the spout will settle on and diminish the sensitivity of the bearing points of the strut. Furthermore, where the strut is located close to the floor, the drippa ge will pile up on the floor and. will clog the bearing points or interfere with the free movement of the strut, or both.

It is another object of this invention to provide a scale mechanism for a parallel beam axis type of machine in I which all of the bearing points are located in an elevated According to my invention, the spout assembly is sus pended from the beam at two spaced points. In the parposition. i

ticular embodiment shown, the spout assembly is in the form of a cradle so that it does not interfere with the location of the various parts of the feeding mechanism. Since thespout assembly is supported at two points it will be stable provided that the center of gravity of the spout assembly system, including theweight of the bag contents, is located between the two points of suspension.

Other objects, features and advantages of my invention will become apparent as the description proceeds.

' With reference now to the drawings in which like reference numerals designate like parts: I

FIG. 1 is a side elevation of a preferred embodiment of my invention;

FIG. 2 is a sectional detail showing the bearing point construction;

sembly 34. I

The feeding mechanism 11 shown herein by way of example comprises a conditioningchamber 12 having as its bottom wall a diffusing pad 13. A flexible flanged tube 14, such as a rubber tube, extends forwardly from an opening in the'front wall of the conditioning chamber 12 and communicates with the rear end of a spout 15 on which the bag is to be suspended. The flanged tube 14 is supported at an intermedate point by a vertical plate 17 whiohismounted on the bed plate 10.

Material is caused to flow from the conditioning chamber 12 through the flanged tube 14 and into a bag 20 when the diffuser pad 13 is energized by means of an air supply 18. Cutoff means to discontinue the feeding operation are provided in the form of a pinch valve 16 for the tube 14. Thefeeding mechanism is described in,

greater detail in'my Patent No. 2,936,994, granted .May 17, 1960, to which referenceis hereby made.

- Scale mechanism is provided to actuate the cutoff means when the weight of the bag contents reaches a predetermined amount. The scale mechanism comprises a beam 25 which is mounted on fulcrum means 21 in such a manner that the fulcrum axis of the beam is parallel to the axis of the spout 15.

The fulcrum means 21 is in the form of a U-shaped structure, shown in FIG. 11, which is disposed adjacent to a flange of thebed'plate 10, as shown in FIG. 3, and

'Which maybe suitably secured thereto and to the cross members of the supporting framework 19. The fulcrum meansis provided with fulcrum points in the form of conical bearing points 22 which, as shown in FIG. 2, are separately formed members of hardened steel which are 'mountedon the fulcrum member 21 by means of a shank 23. i

The beam 25, as shown in FIG. 10, comprises front and rear inverted U-shaped members 26 and 27 which are connected by a longitudinally extending side bar 28.

Hardened bearing pads 29 are set intoeach of the members 26 and 2'7, and the construction is shown in FIG. 2. Each bearing pad 29 is provided with a conical recess 3%) in which the bearing point 22 is received. The bearing pad'29 is also provided with a shank 31 bymeans of V which it can be accurately locatedagainst the shoulder of a oounterhore formed in the members 26 and 27. The bearing point 22 may comprise a 60 cone, and

I the recess 30 may comprise a conical surface, the

radius of the point of the former being of an inch and the radius of the apex of the latter being of an inch. The parts 22 and 29 are preferably made of hardsection taken along line 33 ened tool steel so that they will provide a substantially frictionless and very sensitive bearing surface.

The spout assembly 34 is suspended from the beam at two spaced points. As shown in H6. 9 the spout assembly 34 is a U-shaped member having two support lugs 35 and 36 in which conical bearing pads, similar to the bearing pads 29, are mounted for cooperation with bearing points 37 and 38 which are mounted in the front and rear members 26 and 27 of the beam 25.

The spout assembly 34 includes a mounting plate at which forms the front leg thereof and which is provided, as shown in FIG. 9, with an'opening 4h. The spout 15 is rigidly mounted in the opening so that it forms a part of and moves with the spout assembly. Thus the 'medialplane of the suspended spout assembly 34 will tend to remain vertical during the rocking of the beam 25, and the lever arm, which constitutes the horizontal distance between the fulcrum points 22 and 37, will be maintained constant at all times. According to this arrangement, the location of the bag 2%? upon the spout 15 will not affect the lever arm.

The spout assembly is so designed that the moment of the spout assembly 34 with respect to the front bearing point 37 is greater than the moment of the bag 2b and contents, so as to stabilize the spout assembly against backward tilting. To this end, it may be necessary to add counterweights 42 to the rear portion of the spout assembly 34.

In some types of bag filling apparatus, it is customary to provide a saddle or platform to support the lower end of the bag 24), and in this event, saddle hanger rods 43 may be secured to the lower end of the mounting plate for supporting such saddle.

The beam 25 is loaded by applying a balance weight 44 which is supported from the beam by a bracket 45, the bracket and balance weight being shown in FIG. 8. The beam 25, as shown in MG. 10, may be provided with one or more bearing points 46 for engaging the bracket 45, the latter being provided with conical bearing pads similar to the bearing pads 29. The moment of the balance weight 44 must be sufficient to offset not only the weight of the bag contents, but also the weight of the spout assembly 34, including any counterweights 4-2.

A microswitch Sil is mounted on a suitable bracket 51 (FIG. 1) so that the plunger thereof will be engaged by a portion of the beam 25. In the arrangement shown, the microswitch is a biased open microswitch, the plunger of which is engaged by the underside of the side bar 28. When the weight of the bag contents exceeds the scale setting, then the beam will be tripped, breaking a suitable control circuit which closes the catch valve 16. Preferably, the air supply 18 to the diffuser pad may also be cut off at this time by the control circuit.

Suitable stop means may be provided to limit the throw of the beam. As shown in FIG. 3, the stop means may be in the form of a yoke 52 which is suitably mounted on a bracket 57 and which engages the side bar 28. Screws 53 are preferably threaded into the yoke 52 to provide a fine adjustment, and a similar adjustment is desirably provided for the microswitch in the form of a threaded pin 54 (FIG. 1) which engages the plunger of the microswitch do.

As shown in FIGS. 1 and 42m auxiliary scale beam 55 may be mounted on the front member 26 of the beam 25. A weight as is slidably mounted on the auxiliary scale beam 55. This provides a fine adjustment for the scale mechanism which is particularly useful in changing from one type of bag to another. In other words, hundred pound bags will vary in dimensions according to the type of material being packed, and this variation in dimensions is reflected in variation in weight which may be from a few ounces up to a pound. According to this aspect of my invention, the auxiliary scale beam 55 can be calibrated for different types of bags with the result that in changing over from one material l and bag type to another, it will not be necessary to provide a separate balance weight for each type of bag.

The conical bearing point construction herein shown provides not only a high degree of sensitivity, but it also takes up horizontal forces of considerable magnitude without impairment of accuracy. For instance, one of the difiiculties encountered in the edge disk type of hearing described in my aforesaid copending application is that this type of bearing permits a longitudinal displacement of the beam which in turn increases the clearance between the scale beam 25 and the plunger of the microswitch 50. Any change in clearance reduces accuracy for the reason that it accelerates or retards the reaction interval, that is the interval between initial movement of the scale beam and actuation of the cutoff valve 16. Also, longitudinal displacement destroys the alignment of the pin 54 and the plunger of switch 50.

Longitudinal displacement can occur due to vibration of the beam 25 in the longitudinal direction induced by operation of a bag settler, particularly one of the saddle type which is suspended from the hanger rods 43. Also, in the single point of suspension type of spout assembly, as pointed out in the aforesaid copending application, there is a horizontal reaction force at the bearing point between the spout assembly and the beam, and this will be transmitted to the beam resulting in longitudinal. displacement thereof unless taken up by the bearing points.

In FIG. 12, the spout assembly 34 is supported from the beam 25 only at one point, the bearing point 37, and is stabilized against backward swinging movement by means of a strut 60 or other link which extends between the lower end of the saddle hanger rods 43' and a part of the framework 19. FIG. 12 also shows the saddle or platform 61. The arrangement is otherwise the same as described in connection with FIG. 1.

To summarize the operation, which has heretofore been pointed out in detail in connection with the description of the various parts and subassemblies, the beam 25 1S first loaded with a balance weight 44 selected in accordance with the amount of material to be packed in the bag. Then the bag 20 is slipped over the spout l5 and the filling operation is initiated by causing the pinch yalve 16 to be opened and by supplying air to the diffusing pad 13. At this time the side bar 28 engages the lower arm of the yoke 52 as shown in FIG. 3. Then, when the desired amount of material has been fed into the bag the beam 25 will be tripped causing the beam to be rotated in the counterclockwise direction as viewed in FIG. 4 and operating the microswitch 50 to actuate the cutoff means 16. The flexibility of the tube 14 permits vertical movement of the spout assembly 34 or 34' with respect to the feeding mechanism 11 without detracting from the accuracy or sensitivity of the scale mechanism.

When my invention is used with an auger type filling mechanism, a double tube spout arrangement may be employed to permit free movement of the spout assembly, this arrangement being shown in my Patent No. 2,733,040, issuedlanua'ry 31, 1956.

It will be noted that both the beam 25 and the cradle 34 are shaped so as to avoid interference with the feeding mechanism which extends into the space between the front and rear beam arms 26 and. 27. Thus, my arrangement may be used with various types of feeding mechan1sm, the fiuidizing type being shown herein for purposes of illustration only.

Although only preferred embodiments of this invention have been shown and described herein, it will be understood that various modifications and changes may be made in the constructions shown without departing from the spirit of this invention as pointed out in the appended claims.

The subject matter of my aforesaid copending application, Serial No. 801,143, is incorporated herein by reference, insofar as consistent with the present disclosure,

and the present application forms a continuation-in-part thereof.

I claim:

l. A bag filling machinecomprising material feeding mechanism and scale mechanism for actuating the same, I

said scale mechanism including a beam having spaced front and rear beam arms and a longitudinal connecting member,

a spout assembly supported from said front and rear beam arms, and including a bag supporting spout communicating with said feeding mechanism,

means for mounting said beam on a fulcrum axis which is parallel to the axisof said spout whereby the longitudinal position of a bag which is suspended from said spout will not affect the lever arm of the force exerted by said bag upon said beam,

and means for connecting a balance weight to said beam at a point rearwardly of said front beam arm,

the mass distribution of said spout assembly being such that the center of gravity of the system comprising said spout assembly and the contents of the bag supported thereby will be located between said front and rear beam arms.

2. Abag filling machine comprising material feeding mechanism and scale mechanism,

said scale mechanism including a beam having spaced front andrear beam arms and a longitudinal connecting member,

a suspended spout assembly supported from said beam at two pointsof suspension and including a bagsupporting spout which communicates with said feeding mechanism and which extends forwardly beyond said front beam arm,

fulcrum means for mounting said beam on a fulcrum axis whichis parallel to the axis of said spout whereby the longitudinal position of a bag which is suspended from said spout will not affect the lever arm of the force exerted by said bag'upon said beam,

said feeding mechanism including cutoff means for discontinuing the feeding operation, and

means actuated by the movement of said beam when the material fed into said bag reaches a predetermined weight for actuating said cutoff means, and

balance weight means connected to saidbeam at a point rearwardly of said front beam arm.

3. A bagfilling machine as claimed in claim 2 in which said two points of suspension are aligned substan tially parallel to. said fulcrum axis.

4. A bag filling machine as claimed in claim 2 in which said suspended spout assembly is in the form'of a cradlewhich is supported from said front and rear beam arms.

5. bag filling machine as claimed in claim 2 in which'said suspended spout assembly isin the form of a cradle, the alignment of said points of suspension being substantially parallel to said fulcrum axis, and the mass distribution of said spout assembly being such that the center of gravity of the system comprising said spout assembly and the contents 'ofthe bag supported thereby Will'be located between said front and rear beam arms in order to stabilize said spout assembly against back-' ward swinging movement.

'6. A bag filling machine as claimed in claim 5 which includes a counterweight mounted on said cradle.

8. In a bag filling machine which includes material feeding mechanism having cutoif means for discontinuing the feeding operation, and scale mechanism for actuating said cutoff means, said scale'mechanism including a beam having spaced front and rear beam arms and a longitudinal connecting member, and two'longitudinally' spaced fulcrum members engaging said two beam arms for supporting said beam about a longitudinal fulcrum axis, the combination of aspout assembly suspended from said beam on one side of said fulcrum axis, and a balance weight connected to said beam on the opposite side of said fulcrum axis, said spout assembly comprising a vertically hanging longitudinally disposed U-shaped member supported at its upper ends by said front and rear beam armsand including a longitudinally disposed bag supporting spout communicating with said feeding mechanism, and counterweight means mounted on said spout assembly to prevent same from tipping forwardly due to i the weight of the bag suspended from said spout.

1 References Cited in the file of this patent UNITED STATES PATENTS 2,408,225 Peterson Sept. 24, 1946 2,866,484 Rose Dec. 30, 1958 2,937,863 Hadley May 24, 1960' a FOREIGN PATENTS 634,199 Canada Jan. 9, 1962 795,631 Great Britain s

Claims (1)

1. A BAG FILLING MACHINE COMPRISING MATERIAL FEEDING MECHANISM AND SCALE MECHANISM FOR ACTUATING THE SAME, SAID SCALE MECHANISM INCLUDING A BEAM HAVING SPACED FRONT AND REAR BEAM ARMS AND A LONGITUDINAL CONNECTING MEMBER, A SPOUT ASSEMBLY SUPPORTED FROM SAID FRONT AND REAR BEAM ARMS, AND INCLUDING A BAG SUPPORTING SPOUT COMMUNICATING WITH SAID FEEDING MECHANISM,

Images